I am looking to Bachmann to provide the steam locomotives that I want in N scale.

But, I don't understand the logic of always making new mechanisms that then serves for only one model (maybe with some minor variations).

Why not use the same mechanism to produce other engines that have similar wheel arrangements and driver sizes? For example, a shell for a B&O P7 should be an easy switch for the recently released Pennsy K4 shell. And, with the high headlight position and all-wheel pickup tender, it would make the competition for that model wither and die. And, I am sure that there are other prototypes whose shells that would be suitable for that mechanism, too.

At the same time, a series of new shells on the same mechanism would provide the reason for having a continuing source of mechanism parts to actually repair the engines that have been previously produced with different shells. That continuing part availability would greatly bolster the value of the Bachmann guarantee, which, at this time, really means only that you will get another locomotive type, probably not of your choice, when the one you wanted and bought somehow fails.

It just seems to me that that change in marketing strategy would bolster both our hobby and Bachmann's part in it.

maletrain ,i am on the same page as you &many others here on the forum. in fact i posted much the same as you on july12/2013, again on mar02/14 and again on aug15/2015. from a mfg sense it would seem like the proper path to bring to fruition more new models at the least expense. i would like to see BACHMANN run a survey on this forum as to what the model rail community would like to see for a new steam product release,much the same as kato did ,which i also posted on this forum some time back.bachmann"s northern is just begging for a new release with dcc &sound . so many roads used these ,and the last of them were still operating in canada well into 1962.they were the work horse of the CNR, GTW,CV hauling both freight and passenger be fore falling to diesels.again, like you said the pacific could yeild so many models, streamlined & un shrouded etc.etc. lets see if some more folks respond and if so maybe the administrator will give it some thought with the powers to be and post a survey.regards&later KEWATIN

It is an interesting concept, but I am not sure how practical it would be. There can be as many variables below the running boards as above them just within a single railroad's own stable of x-X-x locomotives. Finding two or more railroads with nearly the same "mechanism" might be very difficult. There are different trailing truck designs, different valve gear designs, and different cylinder sizes, just to name three.

Now, while I am aware that there are differences, I'm a detail novice even on the prototype railroads I hold near and dear to my heart. But then again, I don't model the steam era (at present, at least), so such details don't overly concern me. There are other who are far more... educated than I, and such things would and do matter, to a much greater degree, to them.

There would probably be some design compromises in using a single mechanism under different prototype superstructures. For this to work, Bachmann would need to decide how far they are willing to compromise, how would sales be impacted by such compromises, if the cost savings of a shared mechanism would outweigh any lost sales, and if there is a viable market for the span of models that could use such a shared mechanism. In addition, there is the competition to consider. Would a compromised design B&O P-7 have its potential market vanish if XYZ Model Co. came out with a near-perfect P-7 model?

I feel the biggest obstacle to this might be the "compromise" issue. To the industry's credit, there has been a slow and steady push toward prototype accuracy, even (usually) with the road names and numbers -- the days of Conrail blue steam locomotives and GG-1 electrics riding on a pair of 3-axle diesel trucks, are long behind us. A compromised steam design might be viewed, by us and the companies, as a bit of a back slide toward the old ways.

points are well taken piyer, but i will take the compromise issue any day,as i am not a rivet counter.all that means is we take our modelling skills of acceptance to the level one is comfortable with,after all its my railroad,so whom am i to critisize anyone else. here"s a good xample. there is a well know mfg right now selling conversion kits of the PRR raymond lowerystreamlined pacific for a BACHMANN K4 PACIFIC chassis and they are selling very well.also checking back thru older forums i see that this was the second poll that kato has done. as a strong supporter of bachmann for giving us more steam than most mfg's i would think it be in their best interest to poll members to see what is most wanted? they can do it in n scale or ho as what they do in ho generally ends up ,being produced in n scale.also i along with others would like to see more vandy tenders available.how about it bachmann get those dies out from the mountain or northern locos and run them again? i hope more people put forth their input on this thread,maybe some good will come from it. regards&later KEWATIN

I understand that there are some differences that are noticeable and might be more difficult to switch than others, but really not very many.

To me, the valve gear would be the most difficult, since it is a moving thing that must be made to work with the model mechanism. Still, I would think that Walschaerts and Baker would cover most modern locos, and slide valves would do for most old locos. Many folks can't tell the difference, especially on a model. And, many real railroads switched between one and the other on the same model of locomotive.

Swapping trailing truck types is never a problem, and switching cylinder sizes by a bit of stroke or bore is not such a big deal, either, because the model piston rods simply slide in and out of a hole in the casting. Most of the other detail is on the shell, even the pilot, reverse mechanism, etc. Just look at now different the variations of the K4s are.

I agree that the moderators on this forum are missing a good thing unless they take some poles about what the members here want and think would sell well.

And, I think that Bachmann is missing sales due to its well-known inability to repair most of the models they have issued in the recent past. Especially when quality control from a foreign manufacturer is an issue, domestic repair capability and a parts supply to support it goes a long way toward creating brand loyalty and respect.

Well, making a good shell is not exactly simple. But, it is obviously more simple than making a good shell and a good mechanism that is unique to it. That is the point. Others can make shells with 3D printing and sell them on Shapeways, but those are not going to be as good as shells made with injection molding and individually applied details like Bachmann is doing. And, for pulling power, making the shells out of metal alloy, even if the added details are made of plastic, can greatly enhance the appeal of the loco. Also, because Bachmann typically runs out of mechanisms, hobbists who want to use Bachmann mechanisms for Shapeways shells really need to buy a Bachmann locomtive and trash its shell. That makes that approach more costly than neccessary and suppresses the market for the Shapeways shells.

Doing the research to make a new shell that is a good prototypical representation has sometimes been raised as an impediment to bringing out a new model. But, if the vendors would tap into the various historical societies for the railroads with the prototype engines, they would find that there is a great wealth of information and a group of really dedicated hobbists who would be glad to dig it out and provide it in useful form, because they actually want those modeled and would buy the products.

well,one good thing has already emerged,is the fact the administrator showed up and made a comment sarcastic or not,with a happy face. it shows that mfg's do listen.many of us on this forum are well aware of tooling costs etc,i myself being a retired moulded plastic toolmaker. thats why we are suggesting making alternative shells to fit your chassis.cost savings right there.it would also bring the model to the marketplace much sooner. to say detailed shells from shapeways.are not good quality have any of you modellers seen what SUPERTURBINE has built in the last few yrs using many BACHMANN chassis in his work. you would drool for hours. i think it would be to BACHMANNS credit to do a a forum survey as buyers&supporters of their products to do one. i personally appreciate this forum that they make available and do buy their products ,so what would it hurt the ADMINISTRATOR to put up a starter thread&gauge the results. i think you would be pleasantly surprised at the response. regards&later KEWATIN

If it's the BACHMANN GP40, GP50, U36B... over the years I found that these locomotive shells will fit the same chassis, if it's the Bachmann F9A or the old Minitrix F9A I found that these will fit the old ATLAS / ROCO F9A chassis. Hope this helps.